Grain refinement improves the mechanical properties and formability of metals and alloys. So far, several different grain refinement methods have been proposed and studied. Severe plastic deformation is one of the most promising and efficient methods. Therefore, in the present study the possibility of imposing a two-step severe plastic deformation (Extrusion and Equal channel angular pressing) ...

Optical methods that give displacement or strain fields are now emerging significantly in the mechanical sciences. In the Material Research laboratory at École des Mines d'Albi, we have developed a binocular stereovision system that can be used a) to measure the 3D shape of a static object or b) to measure the deformations of an object undergoing some 3D mechanical or thermal stress. In this pa...

We have investigated the Co-3d spin-orbital state in a thin film of perovskite LaCoO3 to clarify the origin of strain induced spontaneous magnetization (T(C)=94 K) by means of x-ray diffraction, optical spectroscopy, and magnetization measurements. A lattice distortion with the propagation vector (1/4 -1/4 1/4) and an anomalous activation of optical phonons coupled to Co-3d orbital are observed...

Currently, research on structural health monitoring systems is focused on direct integration of the system into a component or structure. The latter results in a so-called smart structure. One example of a smart structure is a component with integrated strain sensing for continuous load monitoring. Additive manufacturing, or 3D printing, now also enables such integration of functions inside com...

This paper presents a study of mechanical behavior of human cancellous bone during a compression loading. Mechanical test is performed inside an X-ray tomography device allowing us to generate a volume image for each loaded step. Digital Volume Correlation (DVC) process has been developed and applied on these volume images. Full 3D displacement field is determined by DVC leading to the calculat...

T he ability to imagine a 3-dimensional (3D) image of the heart was one of the earliest recognized benefits of 2-dimensional (2D) echocardiography at its inception 40 years ago. The ability to build such an image in real time has been a remarkable feat of image processing in the past decade. Intuitively, 3D imaging is the future of echocardiography, and the superiority of this method compared w...

The ability to create extracellular matrix (ECM) constructs that are mechanically and biochemically similar to those found in vivo and to understand how their properties affect cellular responses will drive the next generation of tissue engineering strategies. To date, many mechanisms by which cells biochemically communicate with the ECM are known. However the mechanisms by which mechanical inf...

Many cells in the body reside in a complex three-dimensional (3D) environment stimulated by mechanical force. In vitro bioreactor systems have greatly improved our understanding of the mechanisms behind cell mechanotransduction. Current systems to impose strain in vitro are limited either by the lack of uniform strain profile or inability to strain 3D engineered tissues. In this study, we prese...

The clinical feasibility of 2D elastography methods is hindered by the requirement that the operator avoid out-of-plane motion of the ultrasound image during palpation, and also by the lack of volumetric elastography measurements. In this paper, we develop and evaluate a 3D elastography method operating on volumetric data acquired from a 3D probe. Our method is based on minimizing a cost functi...